Introduction: Laser hair removal (LHR) is a common procedure in dermatology. LHR using quality-switched (QS) 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) is very popular in our community despite lack of sufficient evidence on its efficacy and safety. Purpose: We report the characteristics of nine patients who developed hypopigmented macules after being treated with QS 1064 nm laser for hair removal. Methods: This was a retrospective study at a laser center in Saudi Arabia conducted between June 2014 and September 2018. Patients who developed white macules following treatment with QS 1064 nm Nd:YAG laser for removal of unwanted hair were included in the study. Results: All patients were Saudi females with a mean age of 28.8 years (range: 25–37 years). Well-defined hypopigmented to depigmented 1–3 mm macules developed after being treated with QS 1064 nm Nd:YAG laser for hair removal. The most commonly affected area was the face. Majority of patients had skin phototype IV. Hypopigmented macules developed after an average of 22 laser sessions (range: 4–48 sessions). None of the patients had either personal or family history of vitiligo. Lesions seem to be difficult to treat, with only two patients responding to topical tacrolimus and excimer laser. Conclusion: Hypopigmented macules might develop after QS 1064 nm LHR. Those macules appear to be resistant to treatment. Further prospective controlled studies needed to elaborate more on the safety profile of this procedure.

Laser hair removal (LHR) is a common procedure in dermatology. It is considered a safe and effective method for the removal of unwanted hair for cosmetic and medical reasons such as hirsutism. The use of laser for hair removal can lead to improvement in the quality of life in some patients.[1] LHR is typically performed with different wavelengths in a long-pulsed mode.

Quality-switched (QS) lasers, including QS 1064 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, are used to treat different pigmentary skin conditions such as nevus of Ota,[2] tattoos,[3] and melasma.[4],[5] QS 1064 nm laser has been evaluated only in a few studies for hair removal.[6],[7]

LHR using QS 1064 nm is very popular in our community despite the lack of sufficient evidence on its efficacy and safety. QS LHR has several advantages over conventional long-pulsed laser therapy; those include less associated pain, faster procedure, and possibly lower risk of paradoxical hypertrichosis when treating vellus hair. However, we have noticed that some patients develop treatment-resistant hypopigmentation. Hence, we report the characteristics of nine patients who developed hypopigmented macules after being treated with QS 1064 nm laser for hair removal.

Materials and Methods

This was a retrospective study at a laser center in Riyadh, Saudi Arabia. Ethical approval was obtained from the institutional review board. Medical records of all patients who had white macules following treatment with QS-1064 nm Nd:YAG laser for removal of unwanted hair between June 2014 and September 2018 were reviewed. Skin type, duration of lesions, number of laser sessions, history of vitiligo, comorbidities, and the details of prescribed treatment were obtained for all patients. Data missing from medical records were gathered from clinical photographs and by contacting patients by phone.

Results

A total of nine patients were identified [Table 1]. All patients were Saudi females with a mean age of 28.8 years (range: 25–37 years). The Fitzpatrick skin type ranged from III to V, with the majority having skin phototype IV (66%). The face was affected in all cases [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]. Upper limb and neck involvement were observed in some patients [Figure 2] and [Figure 3]. Lesions were typically well-defined hypopigmented to depigmented 1–3 mm macules. All patients had treatment with QS1064 nm Nd:YAG laser for removal of unwanted hair in those areas with hypopigmented macules. Laser treatments were performed outside our laser center, so the used laser parameters were not available. Disease duration was variable among the study patients ranging from 2 months to over 5 years. Hypopigmented macules developed after an average of 22 laser sessions (range: 4–48 sessions). None of the patients had either personal or family history of vitiligo. No comorbidities were reported except for hypothyroidism in one patient and iron deficiency anemia in another. Tacrolimus 0.1% ointment was prescribed in the majority of patients, which resulted in complete resolution in one patient. Narrowband ultraviolet B, topical corticosteroids, and bimatoprost 0.03% solution were added in some of the patients without additional improvement. One patient significantly improved after a 5-month treatment with a combination of excimer laser and tacrolimus 0.1% ointment.

Lasers play a major role in medical and esthetic dermatology. Laser-assisted epilation is one of the most prevalent procedures in dermatology clinics worldwide.[8] This is due to its many advantages such as high patient satisfaction rate,[9] safety, and longevity of the results[6],[10],[11] in comparison with the other traditional methods of hair removal.[11] Long-pulsed lasers are commonly used for hair removal, especially alexandrite and Nd:YAG lasers with good safety profile even in patients with darker skin colors. This is due to their longer wavelengths which avoid the competition with epidermal melanin.[9],[10] QS lasers are used to treat various skin conditions such as nevus of Ota[2],[12] and tattoos.[3],[13]

To the best of our knowledge, QS 1064 Nd:YAG laser is not commonly used for hair removal with only a few published studies.[14] In Saudi Arabia, hair removal is commonly performed using QS 1064 nm Nd:YAG laser. This method is widely used compared to long-pulsed lasers possibly due to a favorable side effect profile including less associated pain. In addition, it is a preferred method to treat vellus hair due to a theoretical lower risk of paradoxical hypertrichosis. As a hair removal device, QS 1064 nm Nd:YAG is commonly used with the following parameters: spot size 4–6 mm, fluence 2–3 J/cm2, and frequency of 10 Hz. Laser sessions are usually performed every 6–8 weeks.

Unfortunately, QS lasers have several reported side effects including pigmentary changes. Liu and Huo reported a patient with permanent leukotrichia after treating a tattoo with QS 1064 nm Nd:YAG laser.[15] Depigmented facial macules were reported following treatment with QS 1064 nm Nd:YAG laser for melasma and rejuvenation.[16] We report nine female patients who underwent treatment with QS 1064 nm Nd:YAG laser complicated by the development of multiple hypopigmented to depigmented macules on the treated sites. Most of them developed over the face after several laser sessions. Lesions seem to be difficult to treat with only two patients responding to topical tacrolimus and excimer laser. Kim et al. have reported a patient with punctate leukoderma posttreatment with QS 1064 nm Nd:YAG laser for melasma which responded well to excimer laser.[17]

The mechanism of this complication is most probably due to the destruction of the epidermal melanocytes. It is not necessarily to be associated with high fluence, as it has been reported with low fluence laser toning for the treatment of melasma.[16] This can be explained by cumulative melanocyte toxicity which can result in melanocyte destruction after multiple sessions.[16]

Al-Orainni et al. have reported four similar patients with facial depigmented macules following the treatment with QS 1064 nm Nd:YAG laser for hair removal.[18] Up to our knowledge, this is the largest number of patients with this complication following treatment with QS 1064 nm Nd:YAG laser for hair epilation.

Conclusion

We are reporting this complication to increase the awareness about possible side effects of QS 1064 nm Nd:YAG LHR. We also encourage further, larger, and prospective controlled studies to elaborate more on the safety profile of this procedure.